Electrical signals to be transmitted, particularly such electrical signals as are intended to be transmitted using an output driver circuit, have either regularly recurring signal edge changes (e.g. when the electrical signals to be transmitted are clock signals) or irregularly recurring signal edge changes (e.g. when the electrical signals to be transmitted are data output signals from a semiconductor memory). In each case, however, these signals have a fixed period duration and these signal edge changes take place at the end of the latter's period. External influences such as interference affecting switching elements which carry the signal to be transmitted can result in the signal edge changes not taking place exactly when the respective period duration is in progress, however, but rather within a certain interval around this time. This phenomenon, which is general knowledge, is called “jitter” in specialist circles.
In particular, in the case of output driver circuits in integrated semiconductor circuits, such as integrated semiconductor memories, in practice the electrical signal leaving the output driver circuit, and hence the electrical signal leaving the integrated semiconductor circuit, causes interference at edge-change times which has a capacitive and inductive effect (e.g. via the housing mass of the integrated semiconductor circuit) on the supply potentials for the integrated semiconductor circuit, and hence in turn on the output driver circuit. In some cases, these effects are also transferred via the substrate of the integrated semiconductor circuit containing the output driver circuit. If such an edge change affected by interference or causing interference now appears exactly at the time at which the signal to be transmitted within the output driver circuit has a further edge change, this further edge change is subjected to jitter, i.e. the further edge change actually appearing does not take place exactly at the prescribed time. This is then reproduced across all driver stages in the signal path which follow the driver stage at which this jitter appeared for the first time.
In the past, this was not a problem, however, since the period durations of signals to be transmitted were sufficiently long for the edge changes not to be in the critical time range. However, today's “fast” signals have such short period durations that the risk of jitter is no longer negligible.